US2274234A - Oil seal for moving parts - Google Patents

Description

' Feb. 24, 1942. 2 E. D. EKkEBus ETAL OIL SEAL FOR MOVING PARTS Filed Nov. 9, 1940 2 2 Sheets-Sheet l F b 24, 2.- E. D. EfKKEBus Em 2,274 234 OIL SEAL FQR MQVING PARTS Filed Nov. 9, 1940 2 Sheets-Sheet 2 I72 venfon 270g E ilf veaas' I067? 6. af/qyer a M m :oil seal and jackettherefor. 1 Other purposes will appear fromtimeto time as applied-to a shaft; t

' ingthe employment of aconfining ring;

Fig.5 is a section'on the line 5--5 of Fig. 4;'

' still further variation;

employment of seal; ,1 r s 11 is a planview ore further variant form; and-x 1 I 2 Fig. 12 is a section on the line. l2-.-.l2 of Fig.8.

indicated .by like symbols throughout the specification" and drawings- Patented Feb. 24, 1942 1 2,274,230; w f f o j w ow ym m r l x x Eloy D. Ekkebus, Mount Prospect, and John C. Gallagher,;Chicago, lll., as'signors toChicago BeltingCompany ChicagqIlL, a corporation f of Delaware v Application November 9, 1940, SerlalNo;365,030

'2 Claims. (o l. w s

of a seal whichmay be applied to areciprocating or rotating member, shaft, orqthe like.

Another purpose is the provisionof sucha seal which iselfective to prevent escape of a fluid lubricantthrough an aperture through which passes a shatter the like.

1 Another purpose isthe provision of such a sealas will simultaneously prevent the escape of. lubricant and the penetration 'of dust, grit,

or other foreign material. 1

.Another purpose is the provision-of an improved oilseal forshafts and the like which shall' have a "vastly longer life thanioil seals currentlyiavailable in the art- 1 ,Anotherpurposc is the provisionpf a combined in the course of the specification and claims.

.We illustrate our invention more or less diagrammatically in .the

accompanying drawings wherein:

elevation of one form of our Fig. 1- is a side device; 3 l 1 Fig. ,2 Ba section on the line-,2-2 of Fig; 1; Fig. 3 is a similar section illustratingthe seal ig. 4 is an elevation similar to-Fig. 1, illustrat- Fig. 6-isa view similar-to Figs. 1 and 4, ofia Fig. 7 is a section on the use i-giurrig. s;

i .Fig. 8 is asimilar view of a variant form;

-Fig. 9 is a-section on the line, 9-9 of. Fig. 8;

Fig. 10.is a similar section, illustrating the a confining metal ring with the :"Like parts are Referring to the drawingshl generallyindi- Our invention relates an improvement in =oil seals,"and has for one purpose the provision channel 'I'."-' Each such: lip portionhas an inner generally cylindrical surface 8, 9, these surfaces being slightly tapered, with their edge of minimum diameter located outwardly, as at "I101 ;,.and II. This slighttaper is sufficient to cause the thrust against the shaft -l2 whenthe sealing r-ing is mounted on a shaft. 'The'a'ngle, however,.ja'nd the reduced diameter of the 1 faces 8, 9' is slight;

'besufllc'iently smaller in diameter than; the exe' and has been somewhat exaggeratedin Fig. '2. What is-important is that the surfaces 8, 9 shall t'eri'or of the shaft 12, particularly along. the

lip edges l0 and I l,"to maintaina thrust ofthe sealing surfaces so definedagainst the exterior of the shaft 12. i

Referring to'Figs. 4. and 5, we find it frequent- 'ly,if not'generally, desirable to, employsome bonding or confining member, suoh a'sthemetal ring 15, which may be,.if desired, permanently bonded to the seal ring and which serves to con-'- ."fine it'and also to providea metal to metal icontact with anysuitable exterior housing," socket,

abutment,'or thelike, which should be sufficiently tight'to'preventany leakage about'the exterior of the seal. i

zR f -ring '5 Figs. 6 and 7, we illustrate a.

varlant form in which the outer-ring portion [1; is entirely housed within a metal shell having an exterior wall I 8 and side walls 19. These side walls have +an' interior offset portion 20, whichpenetrates'channels 2|, forming an intermediate portion of; the ring of reduced thickness; asat 22.1 The ring then' is extended along ,the'axis of the shaft in opposite directions, as-a't 23,14, to formywhat we may call lip portions,

having-slightly tapered inner faces 25, 26; separated by a channel 21; The lower portions of .theiwalls I 9 are shownas extending outwardly cates "a sealing ring,'herein shown as ,havingan exterior cylindrical surface It will-be understood, of course, that the exterior surface may be'varied or modified to suit the, particular needs as regards the space into which the sealing ring 3, 4 indicate channela which define an inter.-

.mediate. portion of reduced axial length. Ex-

tending radially inwardly are two lip portions 5, 6, which may be separated for example by a 5 advantageous where ametal to metal press fit above the upper surfaces of said lip portions 23, 24. In practice, the gauge of the metal 'may be sufliciently thin andthestock used may be such as to provide a spring, action 'onthe part of the metal, which supplements the compression of the rubberlilcematerialof which'the rin'gis formed. 'In inostf cases, however, this f supplemental metallic spring action is not necessary, and no meansfor employing Jitare shown" in the form 'of* Figs..1to,5; 1,

"In" Figs. jll and 12 we illustrate a variant of the form of Figs. .4 and 5, in which the ring [5a is provided with inwardly-extending flanges 30, 3|, terminating in lips 32. 33, which hook into the channels 3 4. These side walls. of metal are rounding ring 45 of metal or the like.

angle of forty-five'd'egrees in relation to the axis of the ring. The inner surface I may be cy1in-.

drical, and is preferably somewhat less in diametc:- than the diameter of the rod or shaft which faces 42,13, whichmay for convenience be at an it is to surround. The result is a continuing thrust or sealing action of the lip portion l l against the opposed surface ofthe rod. We may, if we'desire, employ a permanently secured sur- It will be realized that, whereas we have described and illustrated a practical and operative device, nevertheless many changes may be made tion. We therefore wish our description and trative or. diagrammatic, rather than as limiting us to our precise showing.

, wherein the description or claims we use the term "rubber substitute, we wish it to be underthe disadvantage of deteriorating upon being subjected to oil or grease. A number of such subalthough not absolutely necessary, to employ a confining means, such for example as the ring of Figs. 4 and 5, or the housing or casing of Figs. 7 and 12. The ring prevents any outward bulge or increase in effective diameter of the seal, which might otherwise take place, and provides a compact sealing element which may be easily applied. The employment of the housing or confining casing of Fig, 12 has the further advantage that the user. can hammer the sealing unit into its seat, a procedure which is common practice. Preferably the housing is so formed, as shown in Fig. 12, so as to confine the outer part of the ring while permitting a certain flexure of the lip portions themselves. As a matter of fact, however, a sealing thrust is obtained rather by thebodily distortion of the material than by the fiexure of in the size, shape, number and disposition of parts without departing from the spirit of our invenvdrawings to betaken as in a broad sense illusstances are available on the market, such for example as Duprene, Neoprena Buna, etc.

, The and operation of our invention are as follows: V

In sealing moving parts, such as rotating vor reciprocating shafts where the speed of rotation .or reciprocation is considerable, a difficult problem is presented. Rubber is not-practical sinceit deteriorates very rapidly. The same is generally true of leather. .Oilseals of rubber or of leather, if they will stand up at all, have to be frequently replaced. We have developed, however,-an oil seal which will prevent theescape of oil alonga shaft and will prevent the penetration of dust or grit'or foreign material along the shaft to the lubricant --containing space, and which at the same time will present, a minimum frictional resistance to the movement of the shaft, and will thus reduce heating to a minimum and lengthen the life of the-seal. We employ rubber substitutw. such as Duprene, Neoprene, Buna, or th like, substances which have the general characteristics of rubber as regards flexibility and compressibility, but which, however, are resistant to heat and to oil and grease. a v a We find it desirableto employ some lubricating agent in the material used, such for example as graphite'or some equivalent therefor. We also find that in practice any one of the above materials will receive by adsorption a certain amount of oil or grease during use. This takes place, for example, in the areas or layers of the seal which areclosest to the moving shaft or member. It is a fact that in use the seals tend to become both tighter and better lubricated by the incorporation-ofa certain amount of the lubricant in the surface layers of the seal, which simultaneously provides lubricant for the seal surface and increases the actual built of thesealing ring, and thus maintains pressure against the face of the metal.- Since these rubber substances tend to build up and swell in use, we find it desirable,

the lip itself, although both may have that effect.

One of the advantages of having an outside metallic ring or housing, such as is shown for example in Figs. 5, 7 and 12, is the advantage of having a metal ,to-metal press fit about the outside of the unit, which will .be sufiiciently tight to prevent anyleakage. 1

In the form shown in g, 7 the metal housing extends inwardly from the outer periphery of the seal toward the shaft, along the outer wall of the lip, terminating short of the extreme outer edge of the lip, so that the flexible lip is free to expandand contract without being too greatly constricted in its movement by the metal housing.

The radial lines shown at 50 in Fig. 6 indicate slots formed in the body of one of the side walls 19. In manufacture this side wall l9 will at one stage in the operation be parallel with th exterior wall I8 and'is subsequently bent into the shape shown in Fig. 7. Notches or slots will be cut in such side wall l9 so that when bent into the shape shown in Fig.- 7 the opposed boundaries of these notcheswill come into contact with one another, producing what is in effects continuous ring.

' this form a relatively thin sheet metal may be employed, and a certain spring action of the metal may be relied upon. In most-instances, however, we find that this is unnecessary, and, for example in the forms other than that of Fig. "I, the thrust of the oil seal against the shaft is obtained by the distortion of the material of the seal itself, and no additional spring action is needed. Actually, the increased size of the shaft in relation to the somewhat smaller diameter of the opposed face of the seal causes an expansion of the seal, and the elastic effectis the maintenance'of a final thrust of the seal against the opposed metallic surface of the shaft.

In the form of Figs. 2, 5 and '7 we'find it desirable to somewhat taper the bore of the seal. For example, referring to Fig. 2, the angle may be anything from 0 to 3. In the form of Figs. 9 and 10 this taper is unnecessary, and the inner surface of the seal, as'at', may be truly cylindrical if desired. The opposite walls of the lip or inner flange may beparallel, and in Figs. 9 and 10 we illustrate the angle as 45, although, of course, a variation from that angle may be employed. The lip so formed is bodily expanded or flexed by the engagement of the cylindrical surface with the outer face of the cylinder, and a constant thrust or pressure is maintained against the surface of the shaft.

If desired, a plurality of bodies "may be used in tandem, one telescoped' within the other if desired. 1

It will be understood that, as to the form of confined in position, and that there is asufllciently tight exterior fit to the outside of the seal.

I have referred in the specification to the metal ring 15, to the outer metal shell having an exterior wall It, and to'the metal ring l5. It will prevent leakage around be understood that, while these members are preferably of metal, they may be of other suitable'material, such as any one. of a number of thermoplastics, or even perhaps of rubber or rubberlike material so treated as to be relatively rigid and metal-like rather than rubberlike in their physical characteristics, the point being that each of these elements is stiffer, harder and very much more resistant to distortion than is the rubberlike body of the seal.

We claim:

1. In a unitary oil seal structure for shafts and the like an integral, annular, relatively massive body of compressible, flexible material, said body having a generally cylindrical exterior surface and generally parallel end faces, said end faces being penetrated by circumferential channels of generally semi-circular cross-section, said channels being locatedsubstantially closer to the inner than to the outer face of said annular body, and penetrating said body'tol a depth substantially less than half the axial length of the body, the inner face of said body being. generally cylindrical and being divided into two parts by a relatively shallow channel having an axial extension exceeding its depth, said inner face at opposite sides of the central channel being slightly oppositely tapered from a minimum diameter at each end toward a maximum diameter adjacent the central channel, the minimumidiameter of the inner face, prior to the application of the oil seal to a shaft, being slightly less than the diameter of the at to which it is applied, the width of the connection between the annular body and the lip portions defined between said channels being greater than the depth of the connecting channels and being sumcient to subject the lip portions as a whole to the compression of the massive permitting a slight flexure annular body, while ofthe lip portions.

2. In a unitary oil seal structure for shafts and the like, an integral, annular, relatively,

massive body of compressible, flexible material, said body having a generally cylindrical exterior surface and generally parallel end faces, said end faces being penetrated by circumferential channels of generally semicircular cross-section, said channels being located substantially closer to the inner than to the outer face of said annular body, and penetrating said body to a depth substantially less than half the axial length of the body, the inner face of said body being generally cylindrical and beingsdivided into twoparts by a relatively shallow channel having an axial extension exceeding its depth, said inner face at opposite sides of the central channel being slightly oppositely tapered from a minimum diameter at each end toward a maximum diameter adjacent the central channel, the minimum diameter of the inner face, prior to the application of the oil seal to a shaft, being slightly less than the diameter of the face to which it is applied, the width of the connection between the annular body and the lip portions defined between said channels being greater than the depth of the connecting channels and being sufficient to subject the lip por-' tions as a whole to the compression of the massive annular body, while permitting a slight flexure of the lip portions. and a shell of metal a surrounding and connected to the massive annular body and conforming to its exterior, generally

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